Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The RNA genome of grapevine leafroll-associated closterovirus-3 (GLRaV-3) was cloned as a cDNA generated from GLRaV-3-specific dsRNA, and a partial genome sequence of 13154 nucleotides (nt) including the 3' terminus was determined. The sequenced portion contained 13 open reading frames (ORFs) potentially encoding, in the 5'-3' direction, proteins of > 77 kDa (ORF1a; helicase, HEL), 61 kDa (ORF1b; RNA-dependent RNA polymerase, RdRp), 6 kDa (ORF2), 5 kDa (ORF3, small transmembrane protein), 59 kDa (ORF4; heat shock protein 70, HSP70), 55 kDa (ORF5), 35 kDa (ORF6; coat protein, CP), 53 kDa (ORF7; diverged coat protein, CPd), 21 kDa (ORF8), 20 kDa (ORF9), 20 kDa (ORF10), 4 kDa (ORF11), 7 kDa (ORF12), and an untranslated region of 277 nt. ORF1b is probably expressed via a +1 ribosomal frameshift mechanism, most similar to that of lettuce infectious yellows virus (LIYV). Phylogenetic analysis using various gene sequences (HEL, RdRp, HSP70 and CP) clearly demonstrated that GLRaV-3, a mealybug-transmissible closterovirus, is positioned independently from aphid-transmissible monopartite closteroviruses (beet yellows, citrus tristeza and beet yellows stunt) and whitefly-transmissible bipartite closterovirus (lettuce infectious yellows, LIYV). However, another alleged mealybug-transmissible closterovirus, little cherry virus, was shown to be more closely related to the whitefly-transmissible LIYV than to GLRaV-3.
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PMID:Nucleotide sequence of the 3'-terminal two-thirds of the grapevine leafroll-associated virus-3 genome reveals a typical monopartite closterovirus. 960 46

Recent observations demonstrated that interleukin-1beta converting enzyme family proteases, now referred to as caspase family, play central roles in apoptosis, or programmed cell death. In this study, we tried to isolate and characterize epidermal caspases. By DEAE-Sephacel anion-exchange chromatography, human cornified cell extract showed two caspase-like fractions (F-I and F-II) with different substrate specificities. These were further purified by Sephacryl S-200, Mono Q ion exchange and Superose 6 gel chromatography. F-I showed a molecular weight of 30 kDa and specifically hydrolyzed acetyl-Asp-Glu-Val-Asp-methylcoumarinamide, a fluorogenic substrate for caspase-3 (CPP32) with a Km value of 13.8 microM. F-I generated a characteristic 85 kDa fragment from poly(ADP-ribose) polymerase. Inhibitor susceptibility of F-I was very similar to that of caspase-3, further confirming the caspase-3-like properties of F-I. In contrast, the molecular weight of F-II was estimated to be 110 kDa, which was much higher than the other caspases. F-II equally hydrolyzed acetyl-Asp-Glu-Val-Asp-methylcoumarinamide, and acetyl-Tyr-Val-Ala-Asp-methylcoumarinamide, caspase-1 (interleukin-1beta converting enzyme)-specific substrate, and was inhibited by acetyl-Tyr-Val-Ala-Asp-aldehyde and acetyl-Tyr-Val-Ala-Asp-aldehyde. Affinity labeling using biotinylated YVAD-cmk demonstrated several positive bands ranging from 25 to 35 kDa, supporting the hypothesis that F-II is a complex of multiple caspases. Reverse transcriptase-polymerase chain reaction analysis demonstrated that among known caspases tested, caspase-1, -2, -3, -4, and -7 were expressed in cultured human keratinocytes. These results suggest that multiple caspases are synthesized in human keratinocytes and are involved in terminal differentiation.
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PMID:Partial purification and characterization of two distinct types of caspases from human epidermis. 974 Feb 25

Mycobacteria are intracellular pathogens that survive and grow in host macrophages. Following phagocytosis, sustained intracellular bacterial growth depends on its ability to avoid destruction by macrophage-mediated host defences such as lysosomal enzymes, reactive oxygen and the reactive nitrogen intermediates. This suggests that the interaction between host cell and microbe is delicately balanced, and can be tipped in favour of either organism. The identification of Mycobacterium tuberculosis H37Rv (MTB) genes expressed within host cells would contribute greatly to the development of new strategies to fight tuberculosis. In the present study, we compared MTB gene expression in the course of intra- (human macrophages) and extracellular growth (Sauton's medium) to ascertain whether differences might occur between gene-expression patterns in the two habitats of replication. Using reverse-transcriptase polymerase chain reaction (RT-PCR) on a group of 14 MTB-Complex-specific genes, we found that MT10Sa (a small stable RNA), 35 kDa (unknown), ahpC (alkyl hydroperoxide reductase, AhpC), sigF (alternative RNA Polymerase sigma factor), and katG (catalase-peroxidase, HPI) genes are expressed in both the environments, while Ag85B, Ag85C (members of the Antigen 85 Complex), rpoV (RNA Polymerase sigma factor) and ESAT6 (early secretory antigen, 6 kDa) are expressed only in the in vitro culture; on the other hand, Ag85A (Antigen 85 Complex), rpoB (RNA Polymerase beta sub-unit), pab (Protein antigen b), invA and invB genes (encoding proteins that show homologies with p60 of Listeria monocytogenes) are expressed only inside the macrophage. Positive RT-PCR products on cDNAs for these genomic regions were not obtained from approximately 1000-fold more bacteria grown in Laboratory Broth. Identification of M. tuberculosis genes expressed in response to phagocytosis by human macrophages increases our basic understanding of the host-pathogen interaction, and helps to identify bacterial factors necessary for in vivo survival and growth.
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PMID:Mycobacterium tuberculosis H37Rv comparative gene-expression analysis in synthetic medium and human macrophage. 1094 May 66

Sulphotransferases are a family of enzymes involved in the metabolism and detoxification of many compounds. Dehydroepiandrosterone (DHEA) sulphotransferase (DHEA-ST), which catalyzes the sulphation of steroids such as DHEA, is present in rat liver and adrenals. Sulphated steroids are present in urine, and many other enzymes which catalyze detoxification reactions are found in the kidney. There are not previous reports of DHEA-ST localization in adult kidney. The activity of DHEA-ST was investigated in adult rat kidney by a radio-isotope assay with DHEA as the substrate. Western blotting was used to assess protein expression, and the localization of DHEA-ST was investigated by immunohistochemistry. The DHEA-ST activity in rat kidney was found to be approximately four times less than that in rat liver. In female kidney, the activity was 1.46 +/- 0.06 nmol/min/microg, and in male kidney the activity was 1.29 +/- 0.09 nmol/min/microg. Investigation of protein expression gave a single band at 35 kDa which signified the presence of this enzyme in both male and female adult rat kidneys. Localization studies showed positive staining at high intensity in the collecting ducts of the medulla and in the S3 portion of the proximal convoluted tubule in the cortex. The distribution within the proximal tubules was restricted to the brush border. Reverse-transcriptase polymerase chain reaction showed DHEA-ST RNA expression in adult rat kidney and liver. The presence of this enzyme and its location in the kidney may suggest that in situ sulphation via DHEA-ST may play an important role in the excretion of endogenous and exogenous compounds.
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PMID:Investigation of the localization of dehydroepiandrosterone sulphotransferase in adult rat kidney. 1101 88

The genome of Maize chlorotic dwarf virus (MCDV; genus Waikavirus; family Sequiviridae) consists of a monopartite positive-sense RNA genome encoding a single large polyprotein. Antibodies were produced to His-fusions of three undefined regions of the MCDV polyprotein: the N-terminus of the polyprotein (R78), a region between coat proteins (CPs) and the nucleotide-binding site (NBS) (R37), and a region between the NBS and a 3C-like protease (R69). The R78 antibodies react with proteins of 50 kDa (P50), 35 kDa (P35), and 25 kDa (P25) in virus preparations, and with P35 in plant extracts. In extracts of the leafhopper vector Graminella nigrifrons fed on MCDV-infected plants, the R78 antibodies reacted with P25 but not with P50 and P35. The R69 antibodies bound proteins of approximately 36 kDa (P36), 30 kDa (P30), and 26 kDa (P26) in virus preparations, and P36 and P26 in plant extracts. Antibodies to R37 reacted with a 26-kDa protein in purified virus preparations, but not in plant extracts. Neither the R69 nor the R37 antibodies bound any proteins in G. nigrifrons. Thus, in addition to the three CPs, cysteine protease and RNA-dependent RNA polymerase, the MCDV polyprotein is apparently post-transitionally cleaved into P50, P35, P25, P36, P30, and P26.
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PMID:Accumulation of maize chlorotic dwarf virus proteins in its plant host and leafhopper vector. 1524 76

Four RNAs from a new plant-pathogenic virus, which we have tentatively named European mountain ash ringspot-associated virus (EMARAV), were identified and sequenced completely. All four viral RNAs could be detected in previous double-stranded RNA preparations. RNA 1 (7040 nt) encodes a protein with similarity to the RNA-dependent RNA polymerase of different members of the Bunyaviridae, a family containing five genera with viruses infecting invertebrates, vertebrates and plants. RNA 2 (2335 nt) encodes a 75 kDa protein containing a conserved motif of the glycoprotein precursor of the genus Phlebovirus. Immunological detection indicated the presence of proteins with the expected size of the precursor and one of its processing products. The amino acid sequence of protein p3 (35 kDa) encoded by RNA 3 shows similarities to a putative nucleocapsid protein of two still unclassified plant viruses. The fourth viral RNA encodes a 27 kDa protein that has no significant homology to any known protein. As is typical for members of the family Bunyaviridae, the 5' and 3' ends of all viral RNAs are complementary, which allows the RNA to form a panhandle structure. Comparison of these sequences demonstrates a conserved terminal part of 13 nt, similar to that of the bunyaviral genus Orthobunyavirus. Despite the high agreement of the EMARAV genome with several characteristics of the family Bunyaviridae, there are a few features that make it difficult to allocate the virus to this group. It is therefore more likely that this plant pathogen belongs to a novel virus genus.
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PMID:A novel, multipartite, negative-strand RNA virus is associated with the ringspot disease of European mountain ash (Sorbus aucuparia L.). 1737 80

Aspergillus nidulans produces StcI esterase, which is involved in the biosynthesis of sterigmatocystin, a precursor of aflatoxins. Previous reports of this esterase in A. nidulans suggest that it is composed of 286 amino acid residues with a theoretical molecular mass of 31 kDa. Various conditions were evaluated to determine the optimal expression conditions for StcI; the highest level was observed when A. nidulans was cultured in solid oat media. Various esterases were expressed differentially according to the culture media used. However, specific antibodies designed to detect StcI reacted with a protein with an unexpected molecular mass of 35 kDa in cell extracts from all expression conditions. Analysis of the gene sequence and already reported expressed sequence tags indicated the presence of an additional 29-amino-acid N-terminal region of StcI, which is not a signal peptide and which has not been previously reported. We also detected the presence of this additional N-terminal region using reverse-transcriptase polymerase chain reaction. The complete protein (NStcI) was cloned and successfully expressed in Pichia pastoris.
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PMID:Molecular characterization of StcI esterase from Aspergillus nidulans. 1944 Jul 4

The complete sequence of four viral RNA segments of fig mosaic virus (FMV) was determined. Each of the four RNAs comprises a single open reading frame (ORF) 7,093, 2,252, 1,490 and 1,472 nucleotides in size, respectively. These ORFs encode the following proteins in the order: RNA-dependent RNA polymerase (p1 264 kDa), a putative glycoprotein (p2 73 kDa), a putative nucleocapsid protein (p3 35 kDa) and a protein with unknown function (p4 40.5 kDa). All RNA segments possess untranslated regions containing at the 5' and 3' termini a 13-nt complementary sequence. A conserved motif denoted premotif A was found to be present in addition to the five RdRp motifs A-F in RNA-1. In phylogenetic trees constructed with the amino acid sequences of RNA-1 and RNA-2, FMV clustered consistently with European mountain ash ringspot-associated virus (EMARaV) in a clade close to those comprising members of the genera Hantavirus, Orthobunyavirus and Tospovirus. The amino acid sequence of the putative FMV nucleocapsid protein encoded by RNA-3 shared identity with comparable sequences of EMARaV and the unclassified viruses pigeonpea sterility mosaic virus (PPSMV) and maize red stripe virus (MRSV). The nucleocapsid sequences rooted the four viruses in a clade close to the genus Tospovirus. Based on molecular, morphological and epidemiological features, FMV appears to be very closely related to PPSMV and MRSV. All these viruses are phylogenetically related to EMARaV and therefore seem to be eligible for classification in the proposed genus Emaravirus, which, in turn, may find a taxonomic allocation in the family Bunyaviridae.
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PMID:Complete nucleotide sequence of four RNA segments of fig mosaic virus. 1977 55